Machine for chamfering dies



Jan. 14, 1947. F. JUDGE MACHINEAFQR CHAMFERING' DIES 3 Sheets-Sheet 1 Filed April 29 1944 INVENTOR.

Jan. 14, 1947. F. JUDGE MACHINE vFOR CHAMFERING DIES Filed April 29, 1944 3 Sheets-Sheet 2 HWENTOR. janzn J BY ATTORNEY.

4411.141947. P JUDGE l 2,414,377

MACHINE FOR CHAMFERING DIES Fiied April 29, 1944 :s sheets-sheet s 13am/fan Judge. BY/PTTOR/VEY, I

Patented Jan. 14, 1947 UNITED STATES PATENT OFFICE ,i

1 Claim.

This invention relates to a grinding machine particularly designed for chamfering the lead ends of the spaced toothed lands of a hollow annular and internally threaded die, such as an acorn die.

It is the general object of my invention to provide improved means by which the lead ends of the lands may be accurately chamfered and thereby sharpened and may also be suitably relieved. I also provide for a quick return of the Wheel and work to their initial relation after the grinding for each land is completed.

A further feature of the invention relates to the provision of improved means for moving the grinding wheel toward and from the work in any angular position of the grinding wheel axis.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

A preferred form f the invention .is shown in the drawings, in which Fig. 1 is a plan View of my improved chamfering machine;

Fig. 2 is an end elevation of the die-holding head, looking in the direction of the arrow 2 in Fig. 1; Y

Fig, 3 is a front elevation of the die-holding head, partly in section and looking in thepdirection of the arrow 3 in Fig. 2;

Fig. 4 is an end elevation of the grinding wheel head. looking in the direction of the arrow i in Fig. 1; and

Fig. 5 is a front elevation of the grinding wheel head, looking in the direction of the arrow 5 in Fig. 4,

Referring to the drawings, my improved die' chamfering machine comprises a work supporting head H and a grinding wheel head G, both mounted on a supporting base or table Il). The grinding wheel head G is pivotally connected by a stud I! to the base Hi, so that it may bg angularly adjusted on the base to vary the chamfer angle. Clamps I2 are provided to hold the grinding wheel head in adjusted angular position.

The work K, shown herein as an acorn die, is mounted at the end cfa work spindle I4 (Fig. 3) and is firmly-secured thereto by a clamping sleeve I5 and lock nut I5 which are threaded on a driving bushing I1. The bushing I1 is secured to the tapered end of the spindle I by an internally anged clamping bushing I8.

The details of construction of the work holder are not claimed herein, as they form the subject matter of a copending application, Serial No.

i 520,917, med Vn--zbniary 3, 1944, which issued as Patent 2,385,922, Oct. 2, 1945.

`The work spindle I4 is rotatably mounted in ball bearings 2Q in a work supportv 2| pivoted work slide 24. The slide 24 is mounted indovetailed guideways 25 (Fig. 2) on a cross slideZB and may be manually adjusted thereon axially of the work spindle by a handle 21 which is operative through the usual feed screw and nut.

The cross slide 26 (Fig. 3) is Similarly mOllnted in dove-tailed guideways 21a on the base ID and may be adjusted forward and rearward on said base by a hand wheel 28v which is operative through another feed screw and nut.

Swinging movement forrelieving purposes is imparted `to the work support 2l by rotation of a cam shaft Sil, mounted in bearings 3| in a rearward extension 32 of the work support 2l.,` A handle 33 (Fig. 1) is provided for manually rotating the cam shaft 30.'

Change gears 35 connect the shaft 30 to the work spindle Id, and the gears 35 are so selected that one revolution of the cam shaft 30 will correspond to an angular advance of the work spindle id equal to the angular relation of successive lands of the die or work K. For a die having four lands, the ratio of movement between the shafts 39 and I4 would be four to one, and the shaft I Il would advance for each revolution of the cam shaft 30.

A scroll @am 31 (Fig. 2) is mounted on the cam shaft 35i and engages a roll 38 rotatably mounted on a stand 39 fixed on the wheel slide 24. As the cam shaft 30 is manually rotated., the cam 31 reacts against the roll 38 and swings the work K toward the grinding wheel W to relieve the chamfered end of the land being sharpened.

As one grinding operation is completed, the shoulder 31a of the cam 31 clears the roll 38 and permits an abrupt return movement of the work holder to its initial position for starting the next grinding operation. Contact of the cam and roll is maintained by the rearward overhang of the work head portion 32. The relieving movement is very slight and the drop of the cam is much exaggerated for clearness.

A work setting arm 49 (Fig. 3) is mounted at the end of a supporting rod 4I slidable in bearings 42 on the top of the work head 2I. Screws G3 hold the rod 4I in adjusted position. When a die is to be mounted on the work spindle, the cam shaft 30 is rotated to bring the cam 31 to starting position. One of the lands of the die or work K is then engaged with the arm 4|) before 3 the flanged bushing I8 is tightened to secure the work holder on the work spindle I4.

The grinding wheel W is mounted on a wheel spindle 5D rotatable in bearings in a wheel support 5I which is slidable axially in a wheel head 52 and which may be secured in axially adjusted position by clamping screws 53. The wheel head 52 is mounted for vertical adjustment in dovetailed guideways 55 formed on` the face of a wheel head support 56. Such vertical adjustment is accomplished by a handle 51, feed screw 58 and nut 59 (Fig. 4).

The support 56 is integral with a wheel head carriage 6B (Fig. 4) mounted on longitudinally extending roller or ball bearings 6l. The Wheel head carriage may thus be moved axially of the grinding wheel spindle and toward land away from the work.

Such movement of the wheel head carriage 60 is, preferablyaccomplished manually through a handv lever E3 mounted on a pivot post 64 (Fig. 4) secured to a bearing plate 65 which is pivoted at Il` .to the base I0 as previously described. The plate 65l supports the ball bearings El. The lever 63 is connected by a link 66 to a` portion of the wheel head carriage 60 and thusvprovides` convenient means for` manually reciprocating the y. grinding wheel axially relative to the work K.

The grinding wheel W may be driven by an electric or airw'motor contained in the sleeve 5I or may Ybe provided, as shown vin the drawings, with a pulley 1! connected by a belt 'H to a larger pulleyrlz on the armature shaft of a motor M. The motor is, mountedY in a support 15 pivoted at 'i6 to theV carriage 50 and is adapted to swing forward' or rearward to maintain uniform belt tension as the wheel head 52 is adjusted Vertically'onthefsupport 56. `A spring 11 tends' to 4 Y swing the motor M with its support 15 rearward to take up any slack in the belt 1I.

My improved grinding machine is thus particularly well adapted for grinding internal or acorn dies, and embodies provision for accurately mounting such a die, for selectively positioning the die both axially and transversely relative to the grinding wheel, for oscillating theY work head and die to relieve the vchamfered cutting edges, for adjusting the grinding wheel angularly and vertically relative to the work, and for `manually reciprocating the grinding wheel toward and away from the work.

I have also provided improved means for quickly returning the work to its initial sharpening position relative to the grinding wheel after sharpening and relieving. each land, and for angularly advancing the Work in predetermined relation to the rotation of the relieving cam.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the detailsr herein disclosed, otherwise than as set forth in the claim, but what I claim is:

Ina die cliamiering machine, a base, a work head mounted to swing on said base about an am's parallel to the work head axis, a work spindle rotatable in said head, means to clamp a die to the end of said work spindle, a positioning arm mounted on said swinging work head and effective to engage a land of the die and to thereby angularly position the work in the work headin every position of said head, a supporting rod on which said arm is freely pivoted and movable into andv out of operative position, clamping Y.

bearings on said work head in which said vrod is `axially and angularly movable, and means to securesaid rod in a selected position in said bearings.

Y FRANKLIN JUDGE. 

